CVE-2026-5484

A weakness has been identified in BookStackApp BookStack up to 26.03. Affected is the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. Executing a manipulation of the argument pages can lead to improper access controls. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 26.03.1 is able to address this issue. This patch is called 8a59895ba063040cc8dafd82e94024c406df3d04. It is advisable to upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product.

The following products are affected by CVE-2026-5484 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-5484.

URL	Resource
https://github.com/BookStackApp/BookStack/
https://github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c406df3d04
https://github.com/BookStackApp/BookStack/releases/tag/v26.03.1
https://github.com/Ghufran2/CVE-Bookstack/blob/main/Permission%20Bypass%20in%20Markdown%20Chapter%20Export
https://vuldb.com/submit/781762
https://vuldb.com/vuln/355091
https://vuldb.com/vuln/355091/cti
https://www.bookstackapp.com/blog/bookstack-release-v26-03-1/